Control instrument



Nov. 23, 1965 P. G. ANNABLE 3,219,804

CONTROL INSTRUMENT Filed June 13, 1962 3 Sheets-Sheet 1 @i 6 PUSH 10' Locx 2O INVENTOR. PAUL G. ANNABLE @M Ma! fiwoal ATTORNEYS.

Nov. 23, 1965 Filed June 13, 1962 FIG. 3

P. G. ANNABLE CONTROL INSTRUMENT 2 Sheets-Sheet 2 INVENTOR.

PAUL G- ANNABLE ATTORNEYS.

United States Patent 3,219,894 coN'rRoL INSTRUMENT Paul G. Annahle, Danbury, (:OIHL, assignor to Connecticut Research Associates, Incorporated, Danbury, Conn. Filed June 13, 1962, S r. No. 202,278 14- Claims. (Cl. 23592) This invention relates to a control instrument and more particularly to an instrument capable of discriminating between motion cycles of different speeds so that only those cycles which take place at a desired speed are recorded. The invention has a number of applications but it has been found particularly useful in the recording of the mixing of concrete in transit. The instrument is constructed to inhibit tampering, insuring a high degree of integrity for the information recorded by the instrument.

In a number of industrial operations close quality control is required for mixing and other operations. Thus it is necessary to keep a count of mixing movements, whether they be rotary or reciprocating, to provide such quality control. In those operations where the speed of the mixer or other moving components is not critical a simple counting device may be used. In a great number of operations, however, the mere counting of cyclical movement is not sufiicient since the speed at which such movements take place may be an important factor.

As an example of those mixing operations wherein both the number of mixing revolutions and the speed of mixing revolutions must be counted for quality control, the mixing of concrete is typical. This is particularly true for transit-mixed concrete wherein mixing revolutions should be counted only above a predetermined minimum mixing speed.

As evidence of the concern for concrete quality control a number of state highway departments will not accept transit-mixed concrete because of difficulty in ascertaining the number of revolutions the batched concrete has undergone at the proper mixing speed. The specifications for such concrete are quite strict since inadequate mixing of the aggregate and cement result in concrete of substantially less strength. Further, too much mixing or mixing at below minimum speed will not meet specifications.

Transit-mix concrete trucks generally have two speeds which are known as agitating and mixing speeds. At agitating speed the mixer is turning very slowly and revolutions of the mixing drum at this speed cannot properly be counted as mixing revolutions. Although requirements will vary with each specific job for which the concrete is required, a minimum mixing speed of 6 rpm. is typical. Prior art devices which merely count drum revolutions are not acceptable for such quality control recording since they cannot discriminate between agitating and mixing speed of the mixing drum.

Another drawback of prior art quality control devices of this type is that they do not inhibit tampering and the integrity of the quality information is questionable.

Accordingly, it is an object of the invention to provide a control instrument to count and record repetitious or cyclical movement.

Another object of the invention is to provide a control instrument of the above character wherein the instrument is capable of discriminating between different rates of movement.

A further object of the invention is to provide a control instrument of the above character which will count and record revolutions.

Another object of the invention is to provide a con- "ice trol instrument of the above character which inhibits tampering with the recorded information.

A further object of the invention is to provide a control instrument of the above character which also records the elapsed time that the instrument is operating.

Another object 'of the invention is to provide a control instrument of the above character for use with a concrete mixer.

A further object of the invention is to provide a control instrument of the above character which is relatively inexpensive to manufacture and is reliable in operation.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings.

FIGURE 1 is a perspective view of the recording portion of the instrument.

FIGURE 2 is a partial side view in partial section of a concrete mixing truck with the instrument installed therein.

FIGURE 3 is a circuit schematic of the instrument.

FIGURE 4 is a perspective view of one of the modules of the present invention.

Referring now to FIGURES l and 2, the instrument in general comprises a case 10 having on its front side an elapsed time indicator 12, a revolution count recorder 14, a lock control button 16, two indicating lights 18, 20, and a coded starter plug 22. On the side of the case 11) is an on-off switch 24 and a power supply line 26.

As shown in FIGURE 2 the recording portion of the instrument may be mounted in a transit-mix truck cab 28 for the quality control of concrete mixed in transit in the drum 30. Adjacent the drum 30 is a sensor switch 32 electrically connected by a cable 31 to the main portion of the instrument in case 10. Switch 32 may be directly actuated by 2. lug 34 on the drum or the switch which may be a magnetic proximity switch actuated by a magnet or bar at 34 on the mixing drum. As is well known in the art, a motor or engine (not shown) is provided for turning the drum 30 at varying speeds.

The instrument as shown is used in a typical quality control operation for transit-mixed concrete as follows. An inspector at the batching plant connects the coded starter plug 22 with a coded volt line plug (not shown) to start the instrument and to reset the elapsed time indicator 12 and the counter 14 back to Zero. The locked light 20, which is preferably red, is illuminated whenever the instrument is turned on and time indicator 12 and counter 14 have been stopped purposely by button 16 or by tampering. Thus, upon starting the instrument, light 20 is extinguished and operating light 18, which is preferably green, is illuminated and the time and counting recorders 12 and 14 are in operation.

The truck now leaves the batching plant and the concrete is mixed in the drum 30 on the way to the job site. As drum 30 rotates, only mixing revolutions are recorded on the counter 14. Any revolutions at the drum 30 that are below a predetermined minimum speed will not be counted. Further, if at any time during transit the driver or anyone else attempts to tamper with the instrument, it will lock out with the time indicator 12 stopped at the time and the counter 14 stopped at its last count. The arrival at the job site of a locked out instrument is good reason to reject the load of concrete.

On arrival the on-site inspector may lock out the instrument by pressing button 16 to record the elapsed time reading and the mixing revolution count. If the load of concrete is insufficiently mixed the truck may be put on a standby basis with its mixer rotating to effect the required number of mixing revolutions at mixing speed.

Referring now to FIGURE 3, the instrument circuitry may be powered by the truck battery 40 during its normal operation. The circuitry generally comprises an elapsed time module 41, a rotation counting switch module 42, a counting circuit module 44 for counting the number of high speed impulses generated by switch 42, and a timing discriminator unit module 46 for disabling counting unit 44 whenever switch 42 is not operated above a predetermined rate. A resetting module 48 is provided for resetting the counting indicator 14 and the elapsed time indicator 12 to zero, and for starting the system for the next operation. A lock-operating module 50 is provided for indicating instrument condition and for disabling the system whenever tampering has occurred.

The circuit is reset by properly energizing the coded receptacle 22, which has a pair of contacts for supplying a 115 volt AC. to momentarily energize resetting relay 52. The remaining contacts are dummy contacts, and are connected together through a shorting bar 54. Thus, when a properly coded mating plug is inserted in receptacle 22, resetting relay 52 will be energized. When resetting relay 52 is energized, its movable contact 56 connects conductor 58 to conductor 60. Conductor 58, as will be explained below, is normally energized at the positive battery potential. Conductor 60 is connected to a first side of holding relay 62, the other side of which is connected to negative conductor 64. Relay 62 upon energization completes a holding circuit through its movable contact 66, which connects positive conductor 58 to the first side of relay 62. Accordingly, relay 62 is energized and locks itself in upon momentary energization of relay 52. Movable contact 68 of relay 62 connects positive conductor 70 to energize conductor 72 so long as relay 62 is energized. Conductor 72 is connected in common to each of movable contacts 74 and 76 of reset relay 52. Accordingly, positive potential is supplied during energization of relay 52 by its movable contact 76 to momentarily energize conductor 80, which is connected to one side of relay 82. The other side of relay 82 is connected to negative conductor 64. Accordingly, relay 82 is energized at this time.

Movable contact 74 on relay 52 also connects the positive potential on conductor 72 to conductor 84, which is connected to the upper side of elapsed time reset solenoid 86 and to the upper side of counter reset solenoid 88. Energization of solenoids 86 and 88 resets elapsed time indicator 12 and counter 14, respectively. The unit is now reset and is ready to begin counting when relay 52 is de-energized by withdrawal of the 115 volt A.C. plug.

Normal operation-cycle counting When resetting relay 52 is thus de-energized, its movable contact 74 connects energized conductor 72 to conductor 90, which is connected to one side of elapsed time motor 12a, the other side of which is connected to negative conductor 64. Accordingly, the elapsed time motor begins to run. Conductor 90 is also connected to a terminal 92 on counter switch plug 94. Plug 94 is illustrated as having five prongs, and would normally be inserted in a similar mating socket 96 on counter switch 32 (shown with alphabetically corresponding connections). Prong 92 accordingly connects energized conductor 90 to movable contact 98 in switch assembly 32. In like manner, mating plug and socket assembly 94 and 96 connect conductor 100 to fixed contact 102 and conductor 104 to fixed contact 106 in switch assembly 32. A further pair of contacts 108 in socket 96 are directly connected together, and accordingly directly connect together conductors 110 and 112, for a purpose to be explained below.

Movable contact 98 in switch 32 normally contacts fixed contact 102 therein, and accordingly energized conductor is normally connected to conductor 100. Each time an operating cycle occurs, movable contact 98 briefly disengages from fixed contact 102 and connects energized conductor 90 through fixed contact 106 and conductor 104. If the elapsed time between successive energizations of conductor 104 is not too long, as measured by the timing circuit in module 46, energization of conductor 104 will actuate counting solenoid 114 in counting module 44 through normally closed contact 116 of relay 82.

Operation of the timing-discriminator unit As noted above, conductor is normally energized through switch module 42, being de-energized briefly only when a cycle is completed. If the cycle takes too long, timing-discriminator module 46 will prevent the operation of counting solenoid 114 when conductor 104 is next energized. This is accomplished by energizing relay 82 and opening its contact 116.

When conductor 100 is energized, the positive potential thereon is applied through normally closed contact 120 of relay 122 to conductor 124. A resistor 126 connects conductor 124 to a first base 128 of unijunction transistor 130, the second base 132 thereof being connected by a resistor 134 to the negative power supply conductor 64. Emitter electrode 136 of transistor is connected to conductor 124 through resistor 138, and is connected by a capacitor 140 to negative supply conductor 64. Transistor 130 may be a GE type 2N49l, although other unijunction transistors may be substituted therefor. As thus connected and biased, transistor 130 presents a relatively high impedance between its base electrodes 128 and 132 until a sufficient voltage is applied between emitter 136 and base 132.

Base 132 is connected to base 142 of NPN transistor 144. Transistor 144 has an emitter electrode 146 connected to negative conductor 64 by diode 148, and has its collector 150 connected through resistor 152 to the negative side of relay 122. A resistor 154 is connected from conductor 100 to the junction between emitter 146 and diode 148, and supplies a suflicient forward current through diode 148 to maintain emitter 146 reversely biased with respect to base 142 until an output is produced by transistor 130. A diode 155 is connected across the Winding of relay 122 to prevent application of destructive transient voltages to the various elements in timing discriminator unit 46 due to the suddenly collapsing magnetic field in winding 122 when conductor 100 is deenergized.

As noted above, switch pole 98 normally connects the positive battery potential on conductor 90 to conductor 100, and de-energizes conductor 100 and connects the positive battery potential to conductor 104 momentarily once each time switch 42 is actuated. This energization of conductor 104 is to actuate solenoid 114 to record a revolution count if too much time has not elapsed since the last occurrence of a pulse on conductor 104. Timing discriminator circuit 46, by energizing relay 122, ener-- gizes conductor 80 and accordingly actuates relay 82 after a predetermined period of energization of conductor 100. Energization of relay 82, by opening contact 116 thereon, disconnects conductor 104 from counting solenoid 114, and prevents its operation.

The positive battery potential on conductor 100 is supplied through movable contact 120 of relay 122 to energize a conductor 124. The component values of resistor 138 and capacitor 140 are so adjusted that the voltage across capacitor 140 rises sufficiently to trigger unijunction transistor 130 when conductor 124 has been energized for a given length of time, for example, after ten,

seconds. When transistor 130 triggers, the output pulse produced at base 132 overcomes the negative back bias between emitter 146 and base 142 of transistor 144, turning transistor 144 on. This sufiiciently increases the current through resistor 152 to energize relay 122.

When relay 122 thus energizes, its movable Contact 156 completes a holding circuit for relay 122, directly connecting the negative conductor 64 to the collector 150. Movable contact 120 on relay 122 de-energizes conductor 124 and applies the positive battery potential on conductor 109 to the upper side of relay 82 by conductor 80. The lower side of relay 82 is connected to the battery supply voltage, and accordingly relay 82 will remain energized so long as relay 122 is energized. As noted above, when relay 82 is energized, its movable contact 116 disconnects conductor 164 from solenoid 114 and prevents recordation of a count when switch pole 98 is next actuated.

The next actuation of switch pole 98 thus provides an ineffectual positive signal on conductor 104 and de-energizes conductor 100, thus releasing relay 122 and deenergizing relay 82. Relay 82 is a dash pot or a like timed release relay, and accordingly, contact 116 remains open suificiently long to prevent energization of solenoid 114, until a count should be recorded. When pole 98 next energizes conductor 190, the timing cycle begins again.

It switch pole 98 is actuated before the end of the timing cycle provided by resistor 138 and capacitor 140, relays 122 and 82 will be de-energized and the positive signal pulse on conductor 104 will actuate solenoid 114. Since at this time conductor 100 is de-energized, the potential between base 128 and base 132 will fall below the potential stored in capacitor 140, permitting discharge of the capacitor 149 through emitter 136, base 132, and resistor 134, thus automatically resetting the timing circuit.

As pointed out above relay 82 is energized through contact 7 6 which is operated by relay 52 upon starting of the instrument. Thus, a first actuation of switch pole 98 will not be counted unless the drum 30 passes through the substantial part of a revolution, allowing contact 116 to close after energization of relay 82.

The safety interlocks In order to prevent unauthorized tampering with the counting mechanism, each of the several modules may be sealed, and is connected to the remainder of the circuit by mating plugs and sockets, preferably of the type similar to radio-tube structures 158, as illustrated in FIG- URE 4. Other than the connections required for the above-described circuitry, each module preferably has a pair of extra prongs 108, which are directly short circuited together, and which are then placed in series between the positive side of the power supply and conductor 58, as illustrated by conductors 110 and 112 in FIGURE 3. In order to simplify the drawings, the contacts 108 on the remaining modules are indicated only schematically, with the interconnecting conductors 119 and 112 being omitted. When any of the modules is removed from the chassis, the positive side of the battery will be disconnected from conductor 58, thus de-energizing relay 62, and accordingly the entire system.

Lock-nut indicator light 20 is connected between the negative supply conductor 64 and movable contact 68 on relay 62, which is connected by conductor 70 to the positive side of the battery 40. Since conductor 70 bypasses each of the contacts 108, light 20 will be energized upon de-energization of relay 62, returning contact 68 to its lower position.

Illumination of light 20 either indicates removal of a module, actuation of lock-out switch 16 or on-oif switch 24, or that fuse 23 has blown. If the instrument is unexplainedly in a lock-out condition upon arrival at a job site, this is basis for rejection of that particular batch of 6 concrete. The system may not be restored to its normal operating condition unless relay 52 is again energized with volt A.C., which as noted above, may only be done by energizing the correct coded pair of terminals in plug 22. Operating light 18 is illuminated only through energization of relay 62 and closing of contact 66.

It should be understood that the timing discriminator circuit of my invention is also useful in counting repetitive motion which occurs below a predetermined speed. Such a counting instrument would be operative by reversing the action of contact 116 and providing the proper time constant for resistor 138 and capacitor 140. Thus, counter coil 114- would be disabled until the elapsing of a predetermined time.

It will thus be seen that the objects set forth above among those made apparent from the preceding descrip tion, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A control instrument comprising, in combination,

(A) sensor means for detecting repetitive motion,

(B) counter means electrically connected to said sensor means for recording detected motion cycles,

(C) and counter disabling circuits electrically interposed between said sensor means and said counter means including,

(1) timing means having an electrically charging network circuit for measuring elapsed time between successive motion cycles,

(2) and disabling switch means connected to and actuated by said timing means to disable said counter means when the elapsed time between motion cycles exceeds a predetermined minimum.

2. A control instrument as defined in claim 1 wherein said disabling switch means includes (A) time delay means for delaying enabling of said counter means for a predetermined length of time after being disabled.

3. A control instrument as defined in claim 1 wherein said timing means comprises,

(A) a charging network having a predetermined time constant,

(B) electronic actuating means having a control input and an output,

(1) said input connected to said charging network,

and

(2) said output connected to said disabling switch means.

4. A control instrument for counting motion cycles, comprising, in combination,

(A) a sensor for detection of motion cycles including (1) a switch pole having first and second positions for establishing alternative electrical circuits,

(B) an electrical counter circuit enabled through the second position of said switch pole,

(1) a disabling relay having normally closed contacts in said counter circuit and having time delay means for delaying enabling of said counter circuit for a predetermined length of time after being disabled,

(C) and timing circuit means for operating said disabling relay comprising,

(1) timed trigger means connected to a power source through the first position of said sensor switch,

(2) a holding relay enabled through the first posi tion of said sensor switch and connected to the output of said trigger means,

(a) said holding relay having contacts connecting said disabling relay to a power source,

(b) and being released upon transfer of said sensor switch pole from its first to its second position.

5. A control instrument as defined in claim 4 wherein said timed trigger means comprises (A) a charging network having a predetermined time constant,

(B) a unijunction transistor having its emitter connected to said charging network,

(C) an amplifying transistor (1) having its base connected to one base of said unijunction transistor, and

(2) having its output connected to initially energize said holding relay when said unijunction transistor conducts.

6. A timing discriminator circuit comprising,

(A) first and second timing supply terminals,

(B) first switching means for alternatively applying a direct current voltage to said terminals or to a counting device,

(C) a series circuit comprising a timing resistor and a capacitor connected between said terminals,

(D) comparator means to discharge said capacitor and produce an output signal when the voltage across said capacitor reaches a given fraction of the direct current voltage applied to said terminals,

(E) and second switching means, responsive to said signal, for removing the direct current voltage from said terminals and for temporarily disabling said counting device.

7. The combination of claim 6 wherein said comparator means comprises a unijunction transistor having (A) a first base connected through a first resistor to said first terminal,

(B) a second base connected to said second terminal through a second resistor,

(C) and an emitter connected to the junction of said timing resistor and said capacitor.

8. A control instrument comprising, in combination,

(A) a counter switch having,

(1) a pole with first and second positions establishing alternative electrical circuits,

(B) an electrical counting device operated through the second position of said pole,

(C) a disabling relay having normally closed contacts between said counter switch and said counting device,

(D) a timing circuit connected to operate said disabling relay after a predetermined period of time,

(1) said timing circuit connected to a power source through the first position of said switch pole, and

(2) having discharging means whereby a new timing cycle is initiated whenever said switch pole is opened and reclosed to its first position,

(E) a holding relay having contact means for supplying power to said pole when energized,

(F) coded means for initially energizing said holding relay, and

(G) a plurality of series connections connecting said holding relay to a power source whereby disconnection of any of said series connections de-energizes said holding relay until re-energized by said coded means.

9. A control instrument as defined in claim 8 wherein said counter switch, said counting device, said disabling relay, said timing circuit and said holding relay are all contained in modules having series connections connecting said holding relay to a power source, whereby removal of any one of said modules de-energizes said holding relay.

10. A control instrument for counting repetitive movement and the elapsed time of such movement, comprising, in combination,

(A) a power source,

(B) a sensor switch having first and second positions establishing alternative circuits with said power source,

(C) a holding relay,

(1) having contacts connecting said power source to said sensor switch,

(D) a coded relay connected to operate said holding relay,

(E) a timing circuit powered through the first of said switch positions and comprising,

(1) a charging network,

(2) a first transistor connected to be triggered by said charging network,

(3) a second transistor connected to amplify conduction of said first transistor,

(4) and switching means connected to the output of said second transistor,

(F) an electrically operated counter connected to the second position of said sensor switch, with (1) a disabling relay having normally closed contacts between said counter and said sensor switch,

(a) said disabling relay being energized through said switching means in said timing circuit,

(b) and having delay means for delaying reclosing of said normally closed contacts for a predetermined period of time after said disabling relay is de-energized,

(G) and a timing device connected to said power source through said holding relay.

11. A control instrument as defined in claim 10 wherein said sensor switch, said holding relay, said coded relay, said timing circuit, said counter and said timing device are contained in (A) modules having pin connections,

( 1) each module having a pair of shorted pins connected in series between said power source and said holding relay,

whereby removal of any module de-energizes said holding relay to lock said counter and said timing device at their last position.

12. A control instrument comprising, in combination,

(A) motion sensing means having (1) first and second alternative electrical outputs,

(2) said first output normally being energized,

(3) said second output being energized once per motion cycle,

(B) an electrically charging timing circuit having an input connected to the first output of said motion sensing means,

(1) said timing circuit having an output and (2) a discharging circuit for discharging said charging timing circuit whenever said first output of said sensing means is de-energized,

(C) an electrically actuated motion counting device energizable through the second output of said motion sensing means, and

(D) counter disabling means connected to the output of said timing circuit.

13. In an electrically operated instrument having a plurality of module plug connections for connection with a power source and with other module circuits, in combination,

(A) a plurality of removable principal circuitry modules,

(1) having a plurality of pin connections,

(a) a pair of said pin connections being electrically connected to each other,

(B) a holding relay switch having (1) normally open holding contacts in an electrical series circuit with a power source through each of said connected pin pairs and said module P (2) a power switch having normally open con tacts connecting a power source with other module circuits,

(a) said power switch contacts being closed by energization of said holding relay,

(3) said holding relay switch being self-holding through said holding contacts after initial energization,

(C) resetting switch means having normally open contacts for connecting said holding relay to a power source when closed, and

(D) coded energizing means for actuating said resetting switch means for initial energization of said holding relay,

whereby removal of one of said modules opens said series circuit to de-energize said holding relay switch and opens 10 said holding and power contacts to de-energize the module circuitry until said resetting relay switch is again energized through said coded energizing means.

14. The combination defined in claim 13 wherein said coded energizing means comprises a plurality of power plug contact pairs for connection to a power source, one of said contact pairs being connected to actuate said resetting switch means and the remainder of said contact pairs being electrically shorted to each other.

References Cited by the Examiner UNITED STATES PATENTS 3,044,699 7/1962 Smith 235 92 OTHER REFERENCES Page 499, 1951-The Radio Amateurs Handbook (American Radio Relay League), T wenty-eighth Edition, TK, 6550, R162, 1951, Scien.

Page 1208, 196lThe International Dictionary of Physics and Electronics, Van Nostrand. (QC, 5, 15.)

MALCOLM A. MORRISON, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,219,804 November 23, 1965 Paul G. Annable It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 9, for "and" read to column 5, line 63, for "Lock-nut" read Lock-out Signed and sealed this 20th day of September 1966.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner of Patents 

1. A CONTROL INSTRUMENT COMPRISING, IN COMBINATION, (A) A SENSOR MEANS FOR DETECTING REPETITIVE MOTION, (B) COUNTER MEANS ELECTRICALLY CONNECTED TO SAID SENSOR MEANS FOR RECORDING DETECTED MOTION CYCLES, (C) AND COUNTER DISABLING CIRCUITS ELECTRICALLY INTERPOSED BETWSEEN SAID SENSOR MEANS AND SAID COUNTER MEANS INCLUDING, (1) TIMING MEANS HAVING AN ELECTRICALLY CHARGING NETWORK CIRCUIT FOR MEASURING ELAPSED TIME BETWEEN SUCCESSIVE MOTION CYCLES, (2) AND DISABLING SWITCH MEANS CONNECTED TO AND ACTUATED BY SAID TIMING MEANS TO DISABLE SAID COUNTER MEANS WHEN THE ELAPSED TIME BETWEEN MOTION CYCLES EXCEEDS A PREDETERMINED MINIMUM. 